Lithium-hydrogen electrochemical secondary batteries (“Li—H2 battery”) have been recently invented (U.S. patent Ser. No. 10/211,494). These batteries are comprised of a reversible Li electrode in an aprotonic electrolyte, a Li−ion conductive membrane and a reversible hydrogen electrode in a protonic electrolyte. By offering of two or three times more specific energy, a Li—H2 battery may require both an electrical source and also a hydrogen source. These requirements can be inconvenient for some applications.